Some coaxial cables have hollow center conductors, primarily as a cost savings, but partially to improve bending and manipulation of the cable. Performance is not affected because the radio frequencies used in coaxial cable travel only on the outermost layer of the conductor. Hollow center conductors allow making pin contact with the inner wall of the center conductor, which permits flush cutting of the cable conductors and dielectric upon installation rather than stripping the outer cable layers off to expose a section of solid inner conductor to permit pin contact with the outer surface of the solid center conductor.
Most components which make contact with hollow center conductors use slotted pins which obtain their contact force from the cantilevered beams formed by the pin fingers that result from forming the slots in the pins. Although good contact is achieved, the force applied by the fingers is present during the insertion process, thus creating high drag throughout the process.